The present invention relates to video camera systems, and more particularly, to synchronizing video signals of two or more video cameras.
A video camera transmits fields or frames of video which comprise lines of video. Each field of video is synchronized to one of a series of vertical synchronization intervals. Each line of video is synchronized to one of a series of horizontal synchronization pulses. The video camera uses an oscillator to generate the vertical synchronization intervals and the horizontal synchronization pulses.
Because each video camera uses a different oscillator, the vertical synchronization pulse and the horizontal synchronization intervals in each camera will be at a different frequency. A minor difference in the frequency of the vertical synchronization intervals or and the horizontal synchronization pulses of various video cameras can cause a disruption in the video picture when multiplexing between the various video cameras. Therefore, there is a need for systems which synchronize the vertical synchronization intervals and the horizontal synchronization pulses of more than one camera.